An RF device often comprises a component with a tunable capacitance value such as a varactor, a diode, or a micro-electro-mechanical system capacitor, abbreviated MEMS capacitor. Such a component needs a bias voltage. Thus, a DC blocking capacitor is placed at least at one terminal of the component with the tunable capacitance value.
International Patent Publication No. WO 2006/065693 A1 refers to a slot antenna having a MEMS varactor for resonance frequency tuning.
International Patent Publication No. WO 2006/129239 A1 is related to a planar antenna assembly with impedance matching. A circuit comprises tunable capacitors which are connected in series.
Publication “Distortion in Variable-Capacitance Diodes,” Robert G. Meyer, Mark L. Stevens, IEEE Journal of Solid-State Circuits, Vol. SC-10, No. 1, February 1975, pp. 47-54 describes circuits with variable capacitance diodes.
International Patent Publication No. WO 2010/106484 A1 is related to a bond frame integrated in electronic circuits. The closed bond frame forms an inductive element. Moreover, a series circuit of a MEMS capacitor and a further capacitor couples two areas of the bond frame. A terminal of the MEMS capacitor is electrically connected to a first area of the bond frame and a terminal of the further capacitor is electrically connected to another area of the bond frame.
In International Patent Publication No. WO 2008/087585 A2, a MEMS system is described which comprises a capacitor switch array. The capacitor switch array comprises series circuits of a capacitor and a MEMS switch. The capacitance value of the capacitor switch array is tuned by setting the MEMS switches in an open or a closed state.